While doing some of the analysis for the resource equalization post, I noticed a common trend in most of the games I saw. In analyzing typical booming and anti-rush build order patterns, I found that most players research CIV1 pretty early and usually build their second expansion town around the 2:00 mark. I also found that a 3-4 hoplite rush could enter enemy territory as early as 2:00. Even the most wary boomer will usually drop a second town before researching MIL1, so it appeared that there was a window of opportunity to easily capture the enemy's first expansion town. On that topic, here's what we said two weeks ago:

Another interesting note is the possibility of a quick attack on the second town at the 2:00 mark. This is less devastating than going after the capital, but it also has a higher chance of victory. There's no chance of a temple. There's fewer villagers who can garrison or repair the city. And you will be attacking almost a full minute before the capital attack. While it seems absurd to pass up the sack bonus, the possibility of taking and holding this town is pretty high. The opponent will probably still be stuck at +60/60 econ and you can send villagers to repair the town and use it as a forward base. Not to mention that you've created a 240 resource differential. You've gotten a town for free while he's still got to build another and go MIL1 and build a barracks right away.

This may be true, but given that the capitol offers a juicy +500-to-all sack bonus, the expansion city seems less attractive as a target. In support of this, at Heavens Forum, Apollyon asserted that "If you can sack the second [city,] you sure as hell can sack the capitol." At first glance, I'd agree with this statement. But after further reflection, there are definitely scenarios where you might be able to sack the expansion while an attack on the capitol might fail. As everyone knows, if you rush and don't capture anything, you're pretty much screwed. So if you've committed to the rush, but your attack on the capitol looks too risky, you might go for the expansion. Examples of when this might be a good idea:

The enemy has scouted you already (i.e. seen your troops and barracks) and is planning defenses at his capitol

The capitol is further back, forcing you to travel through enemy territory. You're likely to be seen, losing the element of surprise

The enemy has built a temple at his capitol adding +25% hit points

The number of villagers near the capitol makes getting slingers in unmolested too risky

So why would this likely be more successful? By attacking the expansion:

You are hitting up to a full minute before a normal ancient rush would occur. 4 HI can be attacking the town usually not later than 2:15-2:30. 4 HI will take down a small city in under 1 minute

The enemy will likely have at most 1-2 villagers nearby to either garrison or attack slingers

The enemy may not even have sufficient food this early to immediately upgrade to MIL1, buying you extra attacking time

Defensive buildings (like temples) won't be built yet on the expansion city

The enemy's barracks will likely be built by the capitol and far enough away from his expansion that he cannot easily get troops into the defense

"Okay, so I can get the town, but I don't get the sack bonus!" Yes, this is true. But all is not lost. Your opponent has just spent 108 food and 120 food and timber building that town. You got it for free. This partly makes up for the huge expense of MIL1, barracks, troops, and foregoing +50 ruins. But no, it's certainly not as good as the sack bonus. The other major difference from the capitol sack rush is here we plan to HOLD the city. You've already got a big lead on local military, all you need to do is maintain that lead and make the appropriate counters. You've now got a bigger production economy than the enemy, so that shouldn't be too hard, although you may have fewer stockpiled resources. Meanwhile, you're going to start using his city as an econ point. And knowing the enemy, you probably just captured his juiciest wood location. Send new villagers from your capitol to use any farms or lumber camps left behind. Don't forget to use a villager to begin repairing the city. Played properly, you WILL assimilate it, and you want to make it as difficult as possible to retake. Unlike a capitol sack, the expansion is closer to our home, so we can continue to reinforce with troops and villagers.

The key to all of this is keeping strict tabs on the enemy. In order to pull this off, you need to know what he's up to.
The enemy has three main strategic choices:

Some combination: train defensive troops and build a second city when he can somewhere else

If the enemy tries lays down a barracks and trains up troops to retake the city, he's likely going to lose. You're already ahead on troops and time is ticking away on the assimilation meter. By the time he gets a barracks up, you should have 4-7 troops: 4 HI and 3 LI. Archers will be his first choice, but those require significant amounts of wealth. You should have enough slingers to deal with those. If you see him making other troop types, ensure you have the right counters. A good player will keep his troops garrisoned until he has enough to attack. You may not know how many or what type of troops he's got until he attacks. This may result in you over-producing or under-producing troops. This is why you have to see if he's building a second city and doing #2 or #3.

Another alternative for the enemy is to ignore your attack altogether and make a new city. This is probably not wise. A second expansion city will fall just as quickly as the first one, particularly if he makes it too far away from any defenses he might have. Also, because you have a large force RIGHT ON HIS DOORSTEP, he has to be wary of you continuing to build up and going after his capitol. At a minimum you should expect a competent player to research MIL1, build a barracks, and train at least a few troops. If he's read the forums, he'll probably build the barracks on the other side of his capitol. This is good for you. It enables you to conduct harassing attack on his capitol or farms with your troops while forcing him to ungarrison his troops to shoo you away. If you sense weakness and think you've got enough troops, a final push on the capitol could win the game, but this is risky.

Probably the best course of action for him is to make a significant quantity of defensive troops (archers & slingers) such that he can fend off any further pushes and build a replacement city. This new city would ideally be placed so that he's got access to wood - his second-best spot - and so it's within range of his barracks, so he can defend both expansion and capitol. His best approach is to milk the remaining econ advantage he has and advance faster to a later age where he can dislodge your troops. This middle ground approach is probably the best for him and the most dangerous for you. If you attack one of his cities and he counters you, then you're likely going to lose the captured town. On the other hand, if you do nothing, he may recover economically.

So it all comes down to maintaining the initiative. The best advantages you have are the already sizable army you've got and its placement right in the heart of his territory. Try to keep tabs on him and keeping your troop strength above his. Probe aggressively for any weaknesses and try to discern his troops strength. And good luck!

UPDATE: I think I'm gonna start calling this the EXPANSION RUSH.posted by Tim at 6:53 AM